A Muslim man who allegedly shot and wounded a Philadelphia police officer in a late-night ambush told investigators he pledged his allegiance to Islamic State and carried out the attack "in the name of Islam," police said.
Officer Jesse Hartnett, who chased and shot Edward Archer, the suspected gunman, even after being wounded, is expected to survive. Officials said the shooting was carried out with a stolen police gun.
The FBI is assisting in the investigation of the Thursday night attack, which comes at a time of heightened anxiety for law enforcement officials after terrorist attacks in Paris and San Bernardino. On Friday, White House officials launched the Countering Violent Extremism Task Force to focus on preventing such attacks.
The shooting's purported connection to the terrorist group Islamic State quickly raised fears among public officials.
"This individual and any who would advocate similar acts are not representative of any religion — they are thugs, and criminals," Sen. Bob Casey (D-Pa.) said in a statement after the shooting. "We have to take every appropriate step to safeguard our communities and ensure safety, while also targeting and destroying terrorists."
Rep. Ed Royce (R-Fullerton), chairman of the House Foreign Affairs Committee, cited the shooting in calling for a stronger plan from the Obama administration to destroy Islamic State.
"As we saw in San Bernardino and now in Philadelphia, terrorists are using safe havens in places like Syria to plan and inspire strikes against the United States," Royce said.
But Philadelphia police said Friday that they didn't know whether Archer, 30, of Yeadon, Pa., who was wounded in the attack, had acted with any help.
The suspect's mother told news reporters that he had recently shown signs of mental illness.
Philadelphia's top police official said Archer "doesn't appear to be a stupid individual, just an extremely violent one."
"According to him, he believed the police defend laws that are contrary to the teaching of Islam," Police Commissioner Richard Ross said in a Friday news conference where officials showed still photos of the attack captured by a surveillance camera.
Hartnett's police cruiser was rolling down a street in West Philadelphia late Thursday night when Archer, who appeared to be wearing a long, light-colored robe, started shooting from across the street, according to police.
Muzzle flashes apparently from the gunman's weapon could be seen in a surveillance video. Archer rushed toward the 33-year-old officer's car, firing at least 11 shots with a 9-millimeter handgun "at close range," Ross said.
"My God, the way he's got his arm inside that vehicle.... He was trying to assassinate this police officer," Ross said.
Hartnett was shot three times in the arm, after which he got out of his car and pursued the gunman, shooting him in the buttocks as he ran away, Ross said.
Other officers arrested Archer nearby, Ross said.
"I'm absolutely amazed that Officer Hartnett is here with us today.... We ask that everyone keep him in your prayers," Ross said.
Hartnett is a Coast Guard veteran, the Philadelphia Inquirer reported.
"He has good determination and he's always wanted to help people and be a policeman," Hartnett's father, Robert Hartnett, 58, told the newspaper.
He said that when he saw his son at the hospital he was groggy, but "he was aware of his surroundings and knew what was going on."
Officials discovered that Archer's weapon was an officer's handgun that had been reported stolen from a home in October 2013, though officials did not know how he got the gun, Ross said.
The suspect's mother, Valerie Holliday, told the Inquirer that her son had been a devout Muslim for "a long time" but that lately he seemed to be showing signs of mental illness.
"He's been acting kind of strange lately. He's been talking to himself ... laughing and mumbling," Holliday told the newspaper. "He's been hearing voices in his head. We asked him to get medical help."
Forty-two police officers were shot and killed in the U.S. in 2015, a decline from 49 shooting deaths in 2014, according to figures compiled by the National Law Enforcement Officers Memorial Fund.
Police deaths have gradually been declining since hitting a peak in the 1970s.